Out of all warrior speccs I find prot to be the most rewarding and engaging. The apm are high and the means of survival are very clear without having too track too many things. Many people find it problematic, that prot warriors lack potent selfheal and require a dedicated healer to stay alive. In return, we take less damage overall, if played correctly. Also, Velhari doesn´t one shot us during P3 :P
We have a tool for physical damage and for unblockable damage. The latter scales with Resolve. I also enjoy, that we have many options to optimize our performance with glyphs and talents and don´t have to stick to the same talents and glyphs for all bosses.
All in all I´d say, that warrior is harder to play then Paladin or DK but can be also more rewarding. This is mainly due to the fact, that we don´t have any reliable tools to use AFTER we messed up. Damage must be anticipated and if we wasted rage and suddenly have to tank something hard hitting, we can get in trouble.